In recent years, head region protection airbag devices that deploy an airbag in a curtain-like manner downward of a roof side rail portion and side airbag devices that deploy, between the chest region or the like of a passenger and a side door, a side airbag housed in a seat back side portion during a side-collision have come to be installed in vehicles as passenger protection assistance devices.
In order to actuate these head region protection airbag devices and side airbag devices, a side-collision detection sensor for detecting a side-collision state becomes necessary, and this sensor is usually disposed on the lower side of the inside of a center pillar (B pillar) or the like.
Here, a body structure for shortening the amount of time of detection by this type of side-collision detection sensor disposed inside a center pillar is disclosed in Japanese Patent Publication No. 3,484,925. To briefly describe, the body structure has a configuration where a cross-sectionally L-shaped reinforcement member is set on a lower portion inside a front side pillar. The reinforcement member has a predetermined dimension in the door anteroposterior direction, and during a side-collision (diagonal collision) against the front side door, the body structure is configured to transmit the acceleration from the lower portion of the front side door to the reinforcement member and further transmit the acceleration from the reinforcement member to an outer side upper portion of a rocker to thereby control transmission loss of the acceleration and finally efficiently and rapidly transmit the acceleration during the diagonal collision to the side-collision detection sensor disposed inside the center pillar.
However, according to the prior art disclosed in Japanese Patent Publication No. 3,484,925, in the case of a side-collision of the side door against a pole, and particularly a side-collision or the like against a pole in a diagonal direction, the amount of time to detect the collision using the side-collision detection sensor becomes longer because the acceleration transmitted to the side-collision detection sensor disposed inside the center pillar is small. Consequently, the body structure disclosed in Japanese Patent Publication No. 3,484,925 has room for improvement in regard to this point.
It will be noted that although several side-collision sensors may also disposed inside the rocker in order to solve this problem, in that case this leads to an increase in cost and the control system becomes complicated.